The invention relates to a data flow component and to its utilization in processor and microprocessor systems, the component serving as a basic building block in a Large Scale Integration (LSI) environment.
Present state of the art systems may utilize general purpose chips that can be used for more than one computer function. For example, an Arithmetic Logic Unit (ALU) function and a control unit function are examples of computer functions that may be implemented by the identical general purpose chip. As chip circuit densities increase, more circuits and hence more functions may be provided on each chip. More functions are achieved merely by generating the various masks used in processing the chip, and additional materials, per se, are ordinarily not needed. A practical constraint is the number of terminals that can be physically placed on a chip. A compromise, therefore, results between available input/output control terminals, the complexity of the function and the number of terminals required to support a given level of complexity.
A similar problem was faced earlier in the integrated circuit art and resulted in a circuit packaging approach for Central Processing Unit (CPU) functions referred to in the art as "bit slicing". The concept of "bit slicing" involves employing a number of identical chips, each of which can typically perform ALU functions on two multiple-bit inputs, the chips operating in parallel to handle operands of, for example, 16 bits. Each of these chips include "mode control terminals" which function to establish and control the assignment of each chip to a preselected slice of the multi-slice word or words being processed.
Many of the second level components employed to implement the ALU function on a bit-slice basis, such as registers and multiplexers, are also employed in the implementation of functions other than ALU functions that are necessary to CPU operations. Thus, additional CPU functions which are separate and distinct from the ALU functions and related control lines may be added to a chip that has been designed to implement an ALU function on a bit-slice basis for assigning the individual chips to preassigned bit positions of a multi-bit ALU function or to non-ALU functions. An example of such a non-ALU function is the control, i.e., addressing of a microcode memory.
The data flow component described herein concentrates only on the data flow portion of a computer system. It may, therefore, be more sophisticated or optimally tailored to that particular application.